Tube sizing apparatus



Dec. 5, 1950 c. E. SNYDER was sxzms APPARATUS Filed Oct. 10, 1947 HL/ZTYTUL C/EEEHUE 523 0 55 Patented Dec. 5, 1950 TUBE SIZING APPARATUS Clarence E. Snyder, Akron, Ohio, assignor to The- B. F. Goodrich (-Jompany, New York, N. Y.,- a)

corporation of New York Application. October 10, 1947, Serial No'. 779,157

3 Claims. 1

rubber-like material and is especially useful in preparing the ends of unvulcanized inner tubes for tires preparatory to splicing the ends to each other.

In the manufacture of tire inner tubes of rubber or other rubber-like material it has been the practice to extrude the unvulcanized rubberlike material to form a straight tubular body of the material and then to bring theends of' the straight tubular body into adjacent relation while they are trimmed and butt-spliced.

In the butt-splicing machine the adjacent ends of the tube are flattened between clamping members and difficulty has been experienced where the two ends of the tube are not ofthe same circumference, and therefore not of the same width when flattened, resulting in splices in which the material of the two ends has been off-set at the splice and therefore thin and weak in the region of the folds of the flattened tube. The introduction of synthetic rubber-like materials in the manufacture of inner tubes, and particularly butyl rubber, has increased these difficulties, as with such rubber-like materials it is even more difii'cult to extrude the rubberlike material to provide a tube of uniform circumference.

It is an object of the present invention to over- 4' come the foregoing and other difficulties in the splicing of tubular articles of unvulcanized rubber-like material. Further objects are to provide for sizing the two ends of tubular material. before splicing to pre-stretch the ends of the tube to uniform dimensions, and: to provide for holding the ends of the tube in stretched condition.

These and other objects will appear from the following description and the accompanying drawings.

Of the drawings:

Fig. 1 is a perspective view of apparatus constructed in accordance with and embodying the invention, parts being broken away.

Fig. 2 is a plan view of the operating portions of the apparatus showing the ends of the tube mounted thereon.

Fig. 3 is a side elevation of the apparatus with an unvulcanized inner tube mounted thereon.

parts being broken away.

Referring to the drawings, the numeral I0 designates a support, which may be the top of a table. Mounted on the support, as by screws II, is a guide-way 12. A pair of spreading members, in the form of blocks (3, M, are slidably mounted in the" guide-way for moveme'fit toward and from each other. The block I 3- has a pair of stretching elements I5, I6 secured thereto and projecting therefrom at one side of the guide-way. The block is has a similar pair of stretching elements IT, 18' secured thereto and projecting in thesame direction. These stretching elements are referablyin the form of round rods, and are so formed that portions thereof adjacent the blocks 13 and M are in parallel relation to each other, the elements I 5, l l being spaced apart from each other by the" same amount as the" spacing 'of. the elementslt, l8. The outer ends of the stretching elements or pinsare bent as. atl-i'm, IBa', l'lza, I Ba' so thatthe ends ll'uag. l'fia'conv'erge toward the: ends Hag. f8a and engage the tubes remote from their" ends to reduce graduallythe stretch of the tube beyondits ends and thereby prevent tearing: or localized weakening of the tube at the ends of the stretching: elements.

The spreading member or block i3 is." arranged to be clamped to the' guide-way, and for this purpose, it is provided with a through slot f9, elongated. in the direction of the: guide wam and a locking screw 20. extends through the slot I 9, threaded into the guide-way I2, to clamp the block inanydesir'edposition;

Means is provided for moving the spreading member or" block I4 toward and from the block [3, and for this purpose, a bifurcated fulcrum block 22 fixedto the guide-way l2, and togg-le means, comprising links: '23, 24', is provided. be. tween the fulcrum block and the stretching 'mem'ber" M. 'I'he'v link. 23 is' pivoted to the fulcrum block at one end by the pin 25, the other endof; thelink being pivotally connected; at 26, to? the" link f li The li'nk- 24 is pivotal-1y connected by a pin 21 to the spreading member or block I 4. A lever 28 is secured in the link 23 and-is so arranged that when the lever is moved to the left, as seen in Fig. 1, the block I4 is moved toward the block l3, and when the lever 28 is moved in the opposite direction, the block i4 is moved away from block I3. In the dead center position of the toggle, where the block M has reached its maximum movement in the direction away from the block l3, the block ll is held in such position by the alignment of the links 23, 24 with each other.

In the operation of the apparatus an unvulcanized inner tube 30 of rubber-like material having open ends 3|, 32 is folded upon itself with its ends in substantially super-imposed relation and laid on the support 1 I). The end 32 of the tube is then slipped over the stretching elements l6, [8, the stretching members being arranged in their closest positions of approach to each other, and the end 3| of the tube is slipped over the stretching elements l5, IT, with the ends of the tube substantially abutting against the blocks l3, It. The toggle lever 28 is then moved to the right, as seen in Fig. 1, thereby moving the blocks I3, it apart and with them the spreading elements, resulting in stretching of the ends of the tube to the same width. The tube is permitted to remain on the stretching apparatus for a length of time at least equal to the cycle of the splicing operation which is sufiicient time forthe unvulcanizing material to become permanently set at the stretched position. In extruding the rubber-like material of the tube the tolerances are so set that the largest bore of the extruded tube within the permitted tolerances will be slightly stretched .when placed on the stretching apparatus. The amount of stretch may be regulated by adjust- ;ment of the block IS with relation to the guide- :way 12.

Due to the fact that both ends of the tube are stretched to the same dimensions, the tube ends fit the splicing members of the splicing machine more accurately and are of uniform Width, so that defective splices are greatly reduced in amount.

Variations may be made without departing jfrom the scope of the invention as it is defined -by the following claims.

I claim:

1. Apparatus for simultaneously stretching a 'pair of open ends of a tubular unvulcanized article of rubber-like material to the same size preliminary to splicing them, said apparatus comprising a pair of spreading members, each member having a pair of spreading elements, all of said 'rspreading elements having portions parallel to each other for engaging the tube at its open ends, and each pair of spreading elements having ends converging toward the elements on the opposite spreading member for engaging the tube remote from its ends to gradually reduce stretching, one

1 element of each pair being adapted to enter one open end of the tube and the other element of each pair being adapted to enter the other open end of the same tube, the parallel portions of the elements adapted to enter each tube being spaced :apart by equal amounts, means for spreading the .members apart to stretch both ends of the tube simultaneously, and means engaging the spread- -irig members for limiting the spreading move- --ment.

2. Apparatus for simultaneously stretching a 'pair of open ends of a tubular unvulcanized article of rubber-like material to the same size pretliminary to'splicing them, said apparatus comprising a pair of spreading members, each member having a pair of spreading elements, all of said spreading elements having portions parallel to each other for engaging the tube at its open ends, and each pair of spreading elements having ends converging toward the elements on the opposite spreading member for engaging the tub remote from its ends to gradually reduce stretch ing, one element of each pair being adapted to enter one open end of the tube and the other element of each pair being adapted to enter the other open end of the same tube, the parallel portions of the elements adapted to enter each tube being spaced apart by equal amounts, and toggle means for spreading the members apart to stretch both ends of the tube simultaneously, said means including means for locking said members in spaced-apart relation, and means engaging the spreading members for limiting the spreading movement.

3. Apparatus for simultaneously stretching pair of open ends of an unvulcanized tube of rubber-like material to the same size pr iminary to splicing them, said apparatus cempr ing means for supporting the tube of material with its ends adjacent each other in superimposed relation, a pair of spreading members each having a pair of stretching elements having portions thereof extending therefrom in parallel relation to enter the open ends of the tube, -.vith one element of each pair engaging one end of the tube and the other element of each pair engaging the other end of the same tube, the parallel portions of the elements for entering one end of the tube being equally spaced from each other relative to the elements adapted to enter other end of the tube, the elements of each spreading member having portions beyond said parallel portions converging toward the elements of the opposite spreading member, means for spreading the stretching members apart to simuitaneonsiy stretch the two ends of the tube, and means engaging the spreading members for limiting the spreading movement.

CLARENCE E. SNYDER.

REFERENCES CITED Ihe following references are of record in the file of this patent:

UNITED STATES PATENTS 

